Railroad trains are generally powered by multiple locomotives. The engineer and fireman in the lead locomotive control that locomotive and remotely control the other locomotives in the train. Control of the locomotives in a train is accomplished by wireless radio control through a device such as a GE-Harris controller, sometimes called a GE-Harris Locontrol.
Additionally, because the days of the caboose are long gone, an end-of-train (EOT) device is used, which device is a radio receiver/transmitter, referred to as a transceiver, which lets the engineer know, through a head-of-train (HOT) device located in the lead locomotive, that the train is still intact and that the last car in the train is still with the remainder of the train.
Devices such as the GE-Harris Locontrol and the EOT/HOT device are well known to those of ordinary skill in the art. Both devices, however, encounter significant problems when the train enters a tunnel, as these devices use UHF, or other suitable, radio signals, which signals are not reliably transmitted in tunnels. Particularly in the case of long trains and long tunnels, signals from the EOT are completely cut off. While the GE-Harris Locontrol may work with locomotives that are immediately adjacent one another, given the situation as occurs in many places, particularly in the western United States, wherein helper locomotives are inserted into the middle and at the end of the train, control of the remote locomotives by radio signals is not reliable due to the distance between the system components operating on the same train.
A known solution to this problem is to place store-and-forward repeaters along the length of a tunnel. These devices, however, are both costly and somewhat delicate, and required constant maintenance in the tunnel proper to insure safe train operation. Working in an active tunnel carries a certain amount of risk, particularly in lengthy tunnels.
The communication system of the instant invention overcomes these problems by providing an amplified distributed antenna network including receiver/repeater/transmitters to assist communications within a tunnel, to extend the range of radio signals generated by monitoring and control systems carried on board railroad trains to provide safe operation thereof.